MDL-47484 atto_indent: Prevent loss of rangy markers in some cases

lib/editor/atto/plugins/indent/yui/build/moodle-atto_indent-button/moodle-atto_indent-button-debug.js

@@ -62,6 +62,9 @@ Y.namespace('M.atto_indent').Button = Y.Base.create('button', Y.M.editor_atto.Ed
             blockquotes = this.editor.all('blockquote'),
             count = blockquotes.size();
 
+        // Remove display:none from rangy markers so browser doesn't delete them.
+        this.editor.all('.rangySelectionBoundary').setStyle('display', null);
+
         // Mark all existing block quotes in case the user has actually added some.
         blockquotes.addClass('pre-existing');
 

lib/editor/atto/plugins/indent/yui/build/moodle-atto_indent-button/moodle-atto_indent-button.js

@@ -62,6 +62,9 @@ Y.namespace('M.atto_indent').Button = Y.Base.create('button', Y.M.editor_atto.Ed
             blockquotes = this.editor.all('blockquote'),
             count = blockquotes.size();
 
+        // Remove display:none from rangy markers so browser doesn't delete them.
+        this.editor.all('.rangySelectionBoundary').setStyle('display', null);
+
         // Mark all existing block quotes in case the user has actually added some.
         blockquotes.addClass('pre-existing');
 

lib/editor/atto/plugins/indent/yui/src/button/js/button.js

@@ -60,6 +60,9 @@ Y.namespace('M.atto_indent').Button = Y.Base.create('button', Y.M.editor_atto.Ed
             blockquotes = this.editor.all('blockquote'),
             count = blockquotes.size();
 
+        // Remove display:none from rangy markers so browser doesn't delete them.
+        this.editor.all('.rangySelectionBoundary').setStyle('display', null);
+
         // Mark all existing block quotes in case the user has actually added some.
         blockquotes.addClass('pre-existing');